Fuel burner for boilers



Oct. 11, 19 9. L

' w. M. FULTON 2,484,161 FUEL BURNER FOR BOILERS Filed April 4, 1944 v 4Sheefs-Sheet 1 Oct, 11, 1949.

F iled April 4, 1944 w. M. FULTON 2,484,161-

FUEL BURNER FOR BOILERS 4 Sheets-Sheet 2 Oct. 11, 1949. w. M. FULTON ELBURNER FOR BOILERS 4 Sheets-Sheet 3 Filed April 4, 1944 Oct. 11, 1949.w. M. FULTON 2,484,161

FUEL BURNER FOR BOILERS Filed April 4, 1944 4 SheetsSheet 4 PatentedOct. 11, 1949 UNITED STATE FUEL BURNER FOR BOILERS- I Weston M; Fulton,Knoxville, Tenn, assignor to W. J. Savage Company, Inc.

, Knxville, Tenn.,

a corporation of Tennessee. 7 1

Application April 4, 1944, Serial No. 529,502-

This invention relates to an improvement in fuel burners forboilers,;particularly forthe heating of water for hot Water heaters, hotwater furnaces or other types of boilers.

In my companion application on fuel burners,

Serial No. 529,503, filed April4, 1944, now Patent No. 2,444,985,granted July 13, 19.48, I have set forth an improved method of burningfuel, to-' gether with improvements in the burner construc-.

tion, that provide for the burning of solid fuel of different typesunder varying conditions, and obtaining maximum efliciency therefrom.

The object of this invention is to improve the construction of hot waterheaters for boilers and other devices to apply the improved features andcharacteristics of my improved fuel burner thereto, obtaining theimproved heating effect of the water and maximum efiiciency from thesolid fuel.

This object is accomplished by utilizing a rotary burner into which thefuel is supplied, with provision for supplying air to the fuel bed alongthe sides thereof throughout only the portion of the burner covered bythe fuel bed. The construction provides for the circulation of the waterto be heated in heat exchange relation with the burner to obtain maximumheat transfer from the burner to the water, not only cooling the burnerbut also producing the desired heating effect of the water.

I have shown the invention applied in a preferred embodiment thereof,together with a modification, in the accompanying drawings, in which:

Fig. 1 is a side elevation of my burner construction applied to a hotwater boiler;

Fig. 2 is a longitudinal sectional View through the burner, with partsin elevation;

Fig. 3 is a cross section therethrough substantially on the line .33 ofFig. 2, showing the burner;

Fig. 4 is an enlarged cross section through the burner wall;

Fig. 5 is a similar view showing a modified form of tuyeres; 1

' Fig. 6 is a side elevation of the outer end portion of the burner,showing in section a fuel feeding device; and

Fig. '7 isan end elevation thereof.

The invention is shown as applied to a domestic hot water heater orsteam boiler for purpose-of illustration, although it will be evidentthat it may be used in various applications for heating water."

The invention utilizes a rotary burner designated generally by thenumeral I, which is adapted to be mounted at its inner end on support 2,while its, outer end burner head 3;hereinaf-ter described more in de-'is supported by a tail. The burner I is adapted to be rotated in normaloperation, for-,which purpose it is, pro-.1 vided with a surrounding.ring gear 4 adapted to be driven in any suitable manner, as by means ofpinions 5 inrmesh therewith; a nd mounted on shafts 6 (Fig. 1) operatedfrom a driving motor through any desired mechanism-,gas for'instance, bythat set forth in myapplication on fuel burners, Serial No. 529,503.,filed April-.4, 1944, to which reference is made; and this need not. bedescribed more in detail-herein.

In mounting the inner end portion of the burner I on the mounting. plate2,.I-have provided the periphery of the burner: with an annular flange Ihaving the periphery, thereof formed as a section of a sphere from acenter on, the axis of rotationof the burner l. A seatingringB isprovided with a similarly shaped complementary seat 9 in the inner sidethereof into which the'spherical portion of the flange l fits, therebyforming a flexible.

or adjustable ball joint between the members I, 8, which permitsltheburner l;to,be adjusted to different angular positions in theseatingring 8.

The seating ring B extends into a flanged por- I tion IIJ formed onthea'supportingv plate 2, but; is

of appreciably smaller external diameter than the interna1 diameter, ofthe opening within the flange ID of the plate 2, leaving ajspace I Itherebetween. The space I-Iv is adapted to be filled with packing madeofheat refractory material, such as asbestos. This packing is held inplace at the inner side of the space by a flange I2 on the supportingplate Zpand at the outer side, by a packing gland I 3. The packing glandI3 is shown as in the form of a ring of angular cross section, oneflange of which vfits into the space I I between the members 8 'andilll,while the other flange thereof extends outwardlysubstantially parallelwith a flange I4 formed on theseating ring 8.

Interposed between the flange I4 and the outturned flange of the packinggland I3,is a'series" of coiled compression springs I5, distributed atconvenient intervals around the.-burner. springs have their oppositeends abutting against the flanges I3.and'-I4 so that the springsconstantly exert aiforce tending-to .push the gland I3 to the right-inFig; 2; and the seating ring 8,

to the left. This seating ring.,8,:in turn, tends to push the burner Itothe left, against the burner head 3 at the inlet end ofr the burner;thereby maintaining a firm sliding contact between the endsurface'of'the-burner land the inner surface-of thelburner'headi. Thecon- These stant pressure of the springs also maintains the packingtight in the space thereby sealing the crack between these parts. Theseating ring 8 is held against rotation with the burner by means of astud l6 fixed to the supporting plate 2, and having its outer endloosely received in an opening |1 formed in an extended portion of theflange l4 below the burner.

The supporting plate 2 is mounted in upright position by means of boltsl8 embedded in a masonry wall l9, hereinafter described more in detailin connection with the boiler.

The burner head 3 is preferably concave or dish-shaped on its innerside, having an inner face 29 at the periphery thereof, bearing againstthe end of the burner at its periphery. This forms an upstanding supportbearing againstthe open end of the burner in opposition to the seatingring 8, and permitting rotation of the burner relative to the head 3,while thereby closing the outer end of the burner. The head 3 issupported by legs or brackets 2| which are seated upon and secured to abase 22. .The'base 22 is supported upon adjusting screws 23 located atopposite ends thereof and resting upon the floor F of the boiler room.By adjusting the screws 23, it is possible to raise orlower the head 3or tilt the latter, and therebytilt the burner l to different angularpositions relative to the-horizontal, whereby the feeding of fuelthrough the burner may be increased or decreased in speed, as desired.

The burner head 3 is hollow and provided with a water jacket 24 therei'nextending throughout the major portion of the end of the burner for thecirculation of water therethrough. As shown in Fig. 2, this waterchamber-24 has an'inlet 25 at one side thereof and an outlet 26 at theopposite side, as hereinafter described; The head 3 has acentral hubportion 21.

The head 3 is provided also with a circumferentially extending air box28 that extends ar cuatelythroughout' the segment of the burner that "iscovered normally by the fire bed in the burner, as shown in Fig. '7.This air box 28 is open throughout its inner edge at the inner face ofthe burner to supply air thereto. The air box 28 is provided with an airinlet 29 adapted to be coupled with a pipe 30 that extends from a blower3| mounted on the base 22 and operated by an electric motor 32 in theusual way.

Referring to Figs. 2, 3 and 4, the burner I is composed of an inner wall33 of somewhat irregular form in longitudinal section as shown in Fig.2, and also being of zigzag form in cross section, as shown in Figs. 3and-4, and an outer wall 34. The walls 33 and 34 are joined together at35 at the outer end of the burner, leaving thespace within the wall 33entirely open atsaid end, but covered by the head 3 thereof, while thewall 35 is in bearing relation against the face 20 of the head. At theopposite or innerend of the burner, the space within the endof the innerwall 33 is closed by an end wall 36, while the outer wall 34 is closedby an end wall 31. The space between the walls 33 and 34 forms acontinuous open 1 water chamber 38.

Referring to Figs. 3 and 4, the zigzag shape of the inner wall 33provides within its folds alter nating' air passages.39 and waterpassages 40. The water passages '40 are in open communication at theirouter sides with the water chamber 38 between the walls 33 and 34. Thesides of the folds forming the air passages 39 converge toward i thecenter of the burnerrand'are slightly separated at the inner. face. ofthe wall by slots 4| sages 39 and tuyres 4| into and through the fuelbed in the burner to support combustion in the burner and causing thegases liberated from the coal or other fuel to be carried to the surfaceof the fuel bed for complete combustion. At the same time, thecirculation of the water through the water passages 40, alternating withthe air passages 39, serves to cool the outside of the burner bycarrying heat away from the burner in the water circulated through theheating system, thereby obtaining maximum efficiency in the operation ofthe burner.

As shown in Fig. 2, the air passages 39'and slots 4| extend lengthwiseof the burner from the intake end thereof adjacent the wall 35 to apoint adjacent the opposite end of the burner where an annular flange orwall 42 closes the ends of However, the flange or wall 42 has smallorifices 43 there through adjacent the outer portions of the air the airpassages 39 and slots 4|.

passages 39 in communication therewith to allow some air to bedischarged lengthwise from the air passages carrying out of them any ashthat may have dropped into the air passages through the slots 4|.

Spaced toward the inner end of the burner fromthe wall 42 is an inwardlyextending fold formed in the inner wall 33, as indicated at 44, withinwhich fold is an extension of the water chamber 38. This fold 44, spacedaxially from the inner ends of the air passages 39, provides an ashcollecting space or chamber 45 adjacent the ends of the air passages.The discharge into the chamber 45 from the orifices 43 also completesthe combustion in the chamber 45 of any small por-- tion of the fuelwhich passes into this chamber. 1

The chamber 45 has a discharge opening 45 through the infolded portion44 into a discharge chamber 41 that is located between the infolded wallportion 44 and the end wall 36 that closes the inner end of the wall 33of the burner. discharge chamber 41 is provided with a series ofdischarge openings 48 formed as passageways through the walls 3334 todischarge the prod-- nets of combustion from the burner as the latter isrotated.

Extending lengthwise through the burner from end to end thereof is apipe 49. At the inner end of the burner, the pipe 49 extends through thewall 36 and has an Lip-turned end portion 5|] that extends to a pointadjacent the inside surface of the other wall 34 of the burner.

Telescoped over the pipe 49 is a pipe 5l.' The pipe 5| is of appreciablylarger inside diameter than the external diameter of the pipe 49 toprovide a free water passage therebetween as will be evident from Fig.2. At the inner end of the burner, the pipe 5| is sealed with a watertight joint to the end wall 36 and is in open communication with thewater chamber 38 between th'e walls '36 and 31. 5

At the outer end of the burner, both of th I pipes 49 and 5| extendthrough the-hub 21"of the burner head 3 and into or through. acylindrical fitting 52. The pipe 49 haszits' outer end The threaded intoan end closure 53 sealed to the end of the fitting 52 by a detachableconnection therewith as indicated generally at '54, sealing a waterchamber 55 in said fitting. The opposite side of the chamber 55 issealed by a packed piston 56-form'ed or secured on the end of the pipe5|, and which piston 56 separates the chamber 55 from a chamber 51 alsoformed in the cylindrical fitting 52. The chamber 55 is in opencommunication-with the interior of the pipe 5| for free circulation ofwater therethrough.

A pipe 58 is sleeved over the pipe 5|, extending inwardly from the innerend of the cylindrical fitting 52, through the hub 21 and into the openend of the burner I. The pipe 58 has a packed piston connection 59 insealing relation with the inner surface of the hub 21 of the burner head3=,'maintaining the sealing relation during rotation of the piperelative to said head. The pipe 58 extends into the inner end of thefitting-52 and has the space therearound sealed by a packing gland 60 atthe open end of said fitting.

The pipe 58 is of appreciably larger internal diameter than the externaldiameter of the pipe 5| forming a water passage therethrough from thechamber 51. At the inner end, the pipe 58 is sealed by a water tightjoint with an end closure flange 6| surrounding the pipe 5|, but thewater is discharged from the pipe 58 at said inner end through radiallyextending tubes 62 that extend outwardly from the pipe 58 to the innerwall 33 of the burner where they are in open communication with thewater chamber 38, as shown in Fi 3.

Although the interior combustion chamber of the burner is substantiallycylindrical and of uniform diameter throughout its length, the outerwall 34 of the burner is preferably frustoconical with its larger end atthe discharge end of the burner, which facilitates the circulation ofthe water through the water passages and chambers, as indicated by thearrows in Fig. 2.

Although the invention may be applied to any desired system forutilizing hot water, it' is shown as applied to a steam boiler 63(Fig. 1) which may be of conventional or well-known construction. Theboiler 63 has a main steam outlet pipe 64 leading to the radiator systemor other point of utilization of the steam.

- The water jacket of the boiler 63 has a connec- :i'

tion 65 near the lower portion thereof by which an outlet pipe 66 isconnected with the boiler. The pipe66 extends outwardly and downwardlyfrom the connection 65, and passes transversely under the burner, asshown in Fig. 7, thence lengthwise in an outward direction, as shown inFigs. 2 and 6. The pipe 66 has a connection 61 leading therefrom to theinlet of the water chamber 24 in the burner head 3. Another connectionfrom the pipe 66 is indicated at 68, leading to; the water chamber 57 inthe cylindrical fitting 52.

A pipe 69 leads from the water chamber '55 upwardly'and inwardlytherefrom toward the boiler 63, and the pipe 69 is connected with theupper portion of the boiler 63 just below the water line at the point10. The pipe 69 is connected also with the water chamber 24 through aconnecting pipe A pipe 12 is connected with the coupling member 53 inalignment with the pipe 49 interconnected therewith, and extendstherefrom inwardly and upwardly beside the boiler, as shown in Fig. 1,to a steam and water separator 13 of any well-known design. Theseparator.13 is iii connected by'a nipple 14 to the steam outlet pipe 64 of theboiler to discharge any steam from the separator 13 into said steamoutlet ipe. The steam separator 13 is provided also with the usual watercollecting chamber 15 arranged to discharge its water into the boiler 63through a pipe 16 leading to the connection 10. These parts areconnected in the usual steam loop, operated in the usual way well knownin the art.

The burner is here shown as located at one side of the boiler 63. Anopening 11 is formed in the ash pit 78 of the boiler to admit hot gasesber 19 may be plastered with a layer of fire clay so that it will retainthe heat and thereby present a hot surface to the gases passingtherethrough. If desired also, the sides of the chamber 41 may beplastered likewise with fire clay.

Although any suitable means may be used for feeding fuel into the burnerI, such for instance as that set forth in my copending application onfuel burners, Serial No. 529,503 filed April 4, 1944, I have shownanother form of fuel feeding device applied to this burner, asillustrated inFigs. 1 6 and 7.

The burner head 3 has a fuel inlet 8| which is located at the right ofthe center of the head 3, as shown in Fig. 7, in order to avoidinterfering with the pipe connections described above. The fuel inlet'8lextends outwardly and upwardly from the burner head 3, and then isturned back at an angle thereto, as shown at 82, whereby the portion 82is out of direct alignment with the opening into the burner. The section82 is connected directly with an extension 83 of a fuel hopper 84. Thehopper 84 is seated upon a saddle 85 supported by a pedestal 86, whichextends down to and is mounted upon the base 22. l

A conveyor screw 81 is provided within the bottom of the hopper 84mounted on a shaft 88 that is adapted to be rotated in any desiredmanner, preferably by power, such as an electric motor drive, one formof which was shown in my copending application on fuel burners, SerialNo. 529,503, filed April 4, 1944. It is sufficient that the conveyorscrew is driven at such speed as will gradually feed the fuel from thehopper 84 into the passages 8|-82 through which the radiant'heatemitted-through the passagewaysill-82 from the interior of the burnerbecause radiant heat travels only in straight lines. Con-' sequently anyfuel that may remain at the discharge opening of the hopper cannot beignited by radiant heat from Within the burner;

The fuel inlet BI is provided with an'access opening in a side thereofadapted to be closed normally by a door '89. One side of the door ishinged to the inlet 8| to swing open and uncover said opening, while theopposite side is provided with a suitable fastening 90 which will holdthe door in closed position and permit it a avigorous fire, andcontinued with hand feeding until the fire is burning satisfactorily inthe burner. The fan or blower 3| may be started by the motor 32 topromote combustion in the burner and continued in operation during suchhand firing and thereafter.

- When a satisfactory fire has been started and a fire bed accumulatedin the burner, the door 89 may be closed and the burner then operatedmechanically. The rotation of the burner would then be started byestablishing a driving connection to the shafts 6 and the shaft 88operated to feed fuel from the hopper 84 into the upper end of the fuelpassages 8l-82. This fuel drops through the fuel passage into the openend of the burner near the lower edge of the fuel bed as maintainedgenerally at one side of the center of the rotating burner substantiallyin the relation described more in detail in my copending application onfuel burners, Serial No. 529,503, filed April 4, 1944. The feeding offuel should be regulated according to the amount of heat desired, as bymeans of the usual or well-known stoker regulators.

Air is supplied to the burning fuel in the burner l by the operation ofthe blower 3|, through the pipe 30 into the wind box 28, whichdischarges into the ends of the air passages 39. This wind box suppliesair to only those air passages 39 that are underneath the fuel bed inits normal position in the lower left hand segment of the burner rotatedin clockwise direction and extending to a point somewhat above thetransverse horizontal center line of the burner. The air is dischargedthrough the slots M from the passages 39 into and through the fire bed,where it serves not only to support combustion but also to carry upwardfrom the underside of the fuel bed the gaseous products liberated fro-mthe burning fuel in a manner described more in detail in my copendingapplication on fuel burners, Serial No. 529, 503 filed April 4, 1944.

The ashes are carried out of the burner through the chamber 45, opening46, and chamber 41, falling by gravity therefrom through the openings48. These ashes may be collected and discharged in any desired manner,such for instance, as that set forth in my copending application.

As combustion proceeds in the burner, the water in the chamber 38becomes heated. This sets up a convectional circulation, causingrelatively cold water to flow from the bottom of the boiler 93 throughthe pipe 66, from whence a portion thereof is discharged through theconnection 61 into the water chamber 24 in the head 3, and the remainderflows through the connection 68 into the chamber of the cylindricalfitting 52. The water from the chamber 51 flows through the pipe 58 intothe tubes 62, thence into the water chamber 38 between the walls of theburner.

The circulation of the water causes it to flow lengthwise of the burnerfrom left to right in Fig. 2 until it reaches the portion of the waterchamber 38 between the walls 36 and 31. There the water enters the openend of the pipe 5| and travels therein through the center of the burner.A portion of the water from this water chamber also flows into theup-turned end of the pipe 49 through which it flows lengthwise of theburner through the center thereof. The water flowing through the pipe 5|is discharged into. the chamber 55, from which it is directed throughthe pipe 69 to the top connection 10 of the boiler 63. The portion whichflows out throu h the pipe 49 passes through the pipe 12 to theseparator 13, the Water therefrom dropping through the pipe 76 into theboiler at the connection 10. The water which flows through the waterchamber 24 from the connection 61, passes out through the pipe H, thencethrough the pipe 69 to the boiler as described above.

It will be noted that the pipes 5| and 58 rotate with the burner whilethe pipe 49 remains stationary, together with the head 3 and thecylindrical fitting 52. Consequently, the up-turned end 50 remains inthe position shown in Fig. 2, so that any steam which may form in thewater chamber 38 is discharged through the pipe 49 into the separator 13for supply of the steam therefrom to the steam pipe 64. The steam loopdescribed also promotes the circulation of water and the escape ofsteam.

The packing rings used in the piston connections and 59 form tightjoints where the pipe 5| rotates relative to the cylindrical fitting 52and where the pipe 58 rotates relative to the hub 21. These preventleakage between these parts during the operation of the burner.

On large heating installations where very rapid circulation may berequired, a power driven circulating pump may be installed in the pipe63 at some convenient place, such as is indicated at 92. The use of sucha pump would serve to increase the circulation through the system whenthe burner is operated.

The air passages 39 and their outlet slots 4| may be so constructed asto progressively increase the amount of air discharged from the slotsfrom the inlet to the outlet end of the burner, if desired, so as todistribute the air more uniformly along the length of the burner and toprevent its natural tendency from flowing toward the discharge end ofthe burner before passing out through the slots 4|. This may beaccomplished by the location of baffles, as shown at I39, spaced alongthe length of the air passages 39 and of progressively increasing heightfrom the inlet toward the discharge end of the burner, as shown in Fig.2.

Instead of discharging the air radially from the air passages 39, asindicated in Figs. 3 and 4, the burner may be constructed, if desired,to provide a tangential or circumferential discharge of the air from thetuyeres, as shown in Fig. 5. Such a tangential discharge may be providedin various ways, but it is accomplished effectively by securing platesl4! over the discharge slots from the air passages 39' as shown in Fig.5. The plates l4! then direct the air discharged from the air passagesin a circumferential direction around the inner wall 33'. and also tendto keep fly ash from falling into the air passages of the burner.

I claim:

1. In a furnace, the combination of a rotary burner for solid fuel, saidburner comprising a surrounding wall structure of elongated tubular Itheinterior of the burner, means for admitting air to the air passages, andmeans mounting. the burner for rotary movement.

2. In a furnace, the combination of a rotary burner for solid fuel, saidburner comprising a surrounding wall structure of elongated tubular formenclosing a combustion chamber adapted to receive a fuel bed of solidfuel therein, means forming air passages through said wall structure andhaving discharge openings therefrom in the combustion chamber, meansforming a water jacket in the wall structure externally of the airpassages and in heat exchange relation therewith and with the interiorof the burner, means for admitting air to said air passages, means foradmitting solid fuel into the rotary burner, and means for mounting theburner for rotary movement about an approximately horizontal axis.

3. In a furnace, the combination of a rotary burner for solid fuel andcomprising an elongated tubular wall structure enclosing a combustionchamber adapted to contain a fuel bed therein, said wall structurehaving a plurality of air passages extending lengthwise of the burnerabout the combustion chamber and having openings in said chambersubstantially along the length of said chamber, means forming a waterjacket in the wall structure externally of the air passages and betweenair passages in heat exchange relation therewith and with the interiorof the burner, means mounting said burner for rotary movement about anapproximately horizontal axis, means for admitting air to said passagesduring said rotary movement, means for feeding solid fuel into theburner, and means for circulating water into and out of the waterjacket.

4. In a furnace, the combination of a rotary burner for solid fuel andcomprising a surrounding wall structure enclosing a combustion chamberadapted'to receive a fuel bed therein, means connected with the wallstructure for admitting air into the combustion chamber, means forming awater jacket around the combustion chamber in heat exchange relationtherewith, means mounting said burner for rotary movement, and meansextending into said combustion chamber and connected with the waterjacket for circulating water into and out of said water jacket.

5. In a furnace, the combination of a rotary burner for solid fuel andcomprising an elongated tubular wall structure enclosing a combustionchamber constructed to contain a fuel bed in the lower portion thereof,said wall structure having an open end and having a water jacket thereinin heat exchange relation with the combustion chamber, a burner headclosing said open end and in bearing relation therewith, means mountingthe opposite end portion of the burner for rotary movement, means forsupplying air to the portion of the combustion chamber covered by thefuel bed, and means for circulating water into and out of the waterjacket during rotation of the burner.

6. In a furnace, the combination of a rotary burner for solid fuel andcomprising an elongated tubular wall structure enclosing a combustion 10chamber adapted to contain a fuel bed therein, said wall structurehaving an open end and having-a water jacket therein in heat exchangerelation with the combustion chamber, a burner head closin said open endand in bearing relation therewith, means mounting the opposite endportion of the burner for rotary movement, and means for circulatingwater into and out of the water jacket including a pipe connectionextending axially through the burner and connected with the water jacketadjacent one end of the burner and a separate pipe connection for theopposite end portion of the burner.

'7. Ina furnace, the combination of a rotary burner for solid fuel andcomprising an elongated tubular wall structure enclosing a combustionchamber adapted to contain a fuel bed therein, said wall structurehaving an open end and having a water jacket therein in heat exchangerelation with the combustion chamber, a, burner head closing said openend and in bearing relation therewith, means mounting the opposite endportion of the burner for rotary movement, and means for circulatingwater into and out of said water jacket and'including pipes telescopedwith each other and extending through the burner axially thereof formingrespective passageways therethrough, one of said. pipes extending to thetop portion of the water jacket for discharging steam therefrom,'andmeans extending into the opposite end portion of the burner andconnected with the water jacket for circulation of water therethrough.

8. In a furnace, the combination of a rotary burner for solid fuel andcomprising an elongated tubular wall structure enclosing a combustionchamber adapted to contain a fuel bed therein, said Wall structurehaving an open end and having a waterjacket therein in heat exchangerelation with the" combustion chamber, aburner head closing said openend and in bearing relation therewith, means mounting the opposite endportion of the burner for rotary movement, and means for circulatingwater into and out of the water jacket comprising pipes connectedrespectivelywith the opposite end portions of said water jacket, afitting connected with said pipes and having chambers therein incommunication with the'respective pipes, and means for circulating waterinto one of said chambers and out of the other of said chambers.

9. In awfurnace, the combination of a rotary burner for solid fuel-andcomprising an elongated tubular wall structure enclosing a combustionchamberadaptedl to contain a fuel bed therein, said wall structurehaving an open end and having a Water jacket therein in heat exchangerelation with the combustion chamber, a burner head closing said openend and in bearing relation therewith, means mounting the opposite endportion of the burner for rotary movement, and means for circulatingwater into and out of the water jacket comprising pipes connectedrespectively with the opposite end portions of said Water jacket, afitting connected with said pipe and having chambers therein incommunication with the respective pipes, means for circulating waterinto one of said chambers and out of the other of said chambers, saidburner head having a water chamber therein, and means for circulatingwater through said water chamber and connected with the Water supplymeans of the fitting.

10. A rotary burner comprising a tubular wall structure enclosing acombustion chamber, said Wall structure having an open end, a burnerhead fitted over said open end and in bearing relation tubular wallstructure enclosing a combustion chamber, said wall structure includingouter and 'innerwalls enclosing a water jacket therebetween,

an end wall structure closing an end portion of the burner, said innerWall having an inturned portion between said combustion chamber and ithe end Wall structure and cooperating with the end wall structure toform a chamber in said end portion of the burner and having an openingtherein for communication between the combustion chamber and said endchamber to receive products of combustion therefrom, and said endchamber having an outlet through the surround-- ing wall structure ofthe burner to discharge the products of combustion therefrom.

12. A rotary burner comprising a tubular wall structure enclosing acombustion chamber and having an open end, a burner head extending oversaid open end to close said end, means mount- .ing said burner head forbearing relation of one end of the burner thereagainst during rotarymovement of the burner, and means mounting,

the opposite end portion of the burner for rotary movement, said meanscomprising a support, a ring surrounding the burner and bearing thereon, and means interposed between the support and said ring, and normallytending to move the burner toward the burner head to maintain thebearing relation thereagainst during rotation of the burner.

13. In a furnace, the combination of a rotary burner comprising asurrounding wall structure of elongated tubular form enclosing acombustion chamber, means forming air passages lengthwise of the tubularportion of said wall structure and having discharge openings therefromin the combustion chamber, means forming a water jacket in the wallstructure externally of the air passages and in heat exchange relationtherewith and with the interior of the burner, means for admitting airto said air passages and confining the admission of the air to thepassages in the lower portion of the combustion chamber, and meansmounting the burner for rotary movement.

14. In a furnace, the combination of a rotary burner comprising anelongated tubular wall structure enclosing a combustion chamber, saidwall structure having an open end and having a water jacket therein inheat exchange relation with the combustion chamber, a burner headclosing said open end and in bearing relation there with, means mountingthe opposite end portion of the burner for rotary movement, and meansfor circulating water into and out of the water jacket during rotationof the burner.

15. A rotary burner comprising a tubular wall structure enclosing acombustion chamber, said wall structure including inner and outer wallsseparated from each other and enclosing a fluid chamber therebetween,said inner wall being formed approximately zigzag in cross sectioncontinuously around the burner providing spaced air passages extendinglengthwise of the tubular wall structure and separated by fluid passagesof approximately the same area as the air passages, each air passagebeing approximately triangular in cross section and having aconstrictedopening approximately at the vertex thereof in communication with thecombustion chamber, the air passages opening into the combustion chamberand the fluid passages opening into the fluid camber, and means foradmitting air to the air passages for flow therethrough and dischargeinto the combustion chamber.

16. In a. furnace, the combination of a rotary burner for solid fuelopen at one end, said burner comprising an elongated tubular wall havinga fluid jacket therein in heat-exchange relation with the interior of aburner, means mounting said burner for rotary movement and including astationary head covering said open end of the burner, and means forcirculating fluid into and out of the fluid 'jacket and head of theburner during rotation of said burner.

WESTON 'M. FULTON.

REFERENCES CITED .The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 2,165,802 Longtin- July 11, 1939

